Study on the ηπ +π − system in the π −p charge exchange reaction at 8.95 GeV/ c

Abstract

A further study on the ηππ system in the charge exchange reaction π − p→ ηπ + π −n at 8.95 GeV/ c has been performed at KEK. A partial wave analysis was done for three t′ regions, 0–0.05, 0.05–0.20 and 0.20–0.60 (GeV/ c) 2 in the mass range between 1.155 and 1.555 GeV. The IJ pc =00 −+ wave via a 0(980)π intermediate state shows clear peaks of η(1295) and η(1400) in the third t′ region. The state η(1400) shows a mass value of 1388±4 MeV. The 01 ++ wave via a 0π shows also a clear peak of f 1 (1285) in the third t′ region. The higher mass region between 1.51 and 1.83 GeV was also studied for the same three t′ regions. No I=0 pseudoscalar state is seen in the analysis.